Dow AgroSciences LLC 

9330 Zionsville Road 

Indianapolis, IN 46268-1054 

March 7, 2011 

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Document Control Office (7407M) 

Office of Pollution Prevention and Toxics 

U.S . Environmental Protection Agency 

EPA East Building, Room 6428 

1201 Constitution Avenue, NW 

Washington, DC 20460 

Attention: TSCA Section 4 

Final Rule for 19 Orphan High Production Volume (HPV) Chemicals iv 

Letter of Response for Phosphorochloridothioic acid, 0,0-diethyl ester (DEPC~ 

CAS Number: 2524-04-1 

This is a letter of response to the final TSCA Section 4 test rule on 19 HPV "orphan" 

chemicals dated January 7, 2011 (76 FR 1067) for phosphorochloridothioic acid, O, 0-

diethyl ester, CAS Number 2524-04-1, commonly known as diethylchlorothiophosphate 

(DEPCT). 

In the 2006 IUR report, DEPCT was reported as being manufactured by Albermarle 

Corporation and imported by The Dow Chemical Company (Dow). We have enclosed a 

letter from Albermarle which indicates that they exited this business in 2006. Based 

upon this information, it is our understanding that Dow AgroSciences (a subsidiary of 

Dow) is now the sole U.S. importer of DEPCT and there is no commercial manufacture 

in the U.S . DEPCT is used by Dow AgroSciences at a single manufacturing site in 

Midland, Michigan, as a raw material in the production of a FIFRA-regulated pesticide 

product. 

EPA has stated that it is requiring testing of chemical substances in this final test rule 

based on its findings under TSCA section 4(a)(1)(B)(i) relating to "substantial" 

production and "substantial human exposure". It is further stated that "substantial 

production" is generally considered to be aggregate production volume (including 

import) exceeding 1 million lbs per year and "substantial exposure" is generally 

considered to be exposure of 1,000 workers or more on a routine or episodic basis.' 

While Dow AgroSciences imports more than 1 million pounds of DEPCT per year, 

based on the limited operational demands the number of employees with potential for 

exposure is substantially less than 1,000. In fact, for the 2006 IUR Report we reported 

25-50 employees potentially exposed to DEPCT, and for 2011 this number continues to 

reflect annual coverage over all work shifts, not daily individual exposure. 

Employee or worker exposure to DEPCT in the Midland, Michigan operations is 

extremely limited as a result of both adherence to MSDS personal protective equipment 

1 76 FR 1067, January 7, 2011, Section IV.A, p. 1070 

~MDow AgroSciences . 

CONTAINS NO CSj 

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recommendations and employment of strict industrial hygiene requirements established 

by The Dow Chemical Company which operates the production site . While TSCA 

Section 4 testing is triggered in part by substantial human exposure, this does not occur 

during manufacturing operations involving DEPCT. Full protective equipment (eye and 

skin protection) is employed to prevent dermal, eye, and clothing contact and mist or 

vapor inhalation of DEPCT is mitigated through the use of respiratory protection. 

Due to this extremely limited use and limited potential for human exposure, Dow 

AgroSciences believes that DEPCT does not meet the requirements for testing under 

TSCA Section 4 and should be exempted from requirements for testing under this Final 

Rule. 

If, after considering the details of this request, EPA does not agree with the conclusion 

that DEPCT should be exempted from requirements for testing under this Final Rule, it 

would be Dow AgroSciences intent to address all testing requirements for DEPCT 

(phosphorochloridothioic acid, O, O-diethyl ester), CAS Number 2524-04-1, as outlined 

in the Final Rule of January 7, 2011 . 

We would be happy to provide additional information to inform the EPA's decisionmaking regarding DEPCT testing, and also to discuss further our position with you. 

Please feel free to contact me or the Registration Assistant for this product, Joyce Carroll 

(phone: 317-337-4631). 

Sincerely, 

~`1~J 

Kenneth D. Racke, Ph.D. 

Regulatory Manager - U.S . Regulatory 

(317) 337-4654 

Email: kracke@dow.com 

, 

/ 

enc. Copy of letter from Albermarle Corporation dated February 3, 2011 
~'~ ALBEMARLE° J1ICORPORATION 

451 Florida Street Telephone: 225- 188-8011 

Baton Rouge, Louisiana 70801-1765 Facsimile: 225-3H8-76H6 

February 3, 2011 

Paul Vammer 

Business Manufacturing Director 

Dow Agro Science 

9330 Zionsville Rd 

Indianapolis, IN 46268 

Dear Mr. Vammer, 

This is to inform and confirm to Dow Agro Science that Albemarle Corporation, 

effective, January 2006, has ceased production and sales of DECTP 

(phosphorochloriodothioic acid 0,0-diethyl ester (CAS Number 2524-04-1). 

If you have any questions regarding this product please contact our sales 

associate Albert Pacella at 330 953 2321 . 

, 

Regards 

David W. DeCuir 

Business Director, Fine Chemistry Services 

Albemarle Corporation 

cc: Doug Line - Dow Agro Science